Knock off any loose stucco around the window, using a wire brush. You don't need to press down hard — just apply enough pressure to remove any loose stucco and debris.
Clean out the cracks or chips around the window, using a shop vacuum.
Spray metal primer onto the exposed lath, if applicable, and let it dry for between three and four hours.
Pour premixed stucco into a bucket and add water, using a hose. Do not soak the premixed stucco — just dampen it until it is spreadable. Use a trowel to mix it by hand.
Scoop some of the stucco out of the bucket, using the trowel, and fill the cracks or chips in the stucco. Use a whisk brush to create textures similar to those on the stucco around the window while the stucco is still wet.
Allow the stucco to dry for five to seven days, or as long as the manufacturer recommends. Once the stucco is dry, paint the patches with a matching color exterior paint, using a paintbrush.